Refrigerator with high humidity subcompartment



30, 6 P. E. 'KRONENBERGER ET AL 3,394,557

REFRIGERATOR WITH HIGH HUMIDITY SUBCOMPARTMENT Filed April 11. 1967 5 Sheets-Sheet l I NVENTORS 30, 1968-. I P. E. KRONENBIERGER E L 3,394,557

REFRIGERATOR WITH HIGH HUMIDITY SUBCOMPAR'IMENT I Filed April 11, 1967 s Sheets-Sheet 2 32 I I W .72 I I 351 50; 1 Z i. n j Visa/2 [23505 7 @MQa/M ATTORNEY 30, 1968 P. E. KRQNENBER-GER ET AL 3,394,557

REFRIGERATOR WITH HIGH HUMIDITY SUBCOMPARTMENT INVENTORS Paul 5 16m ii BY 61m fl'azmel, &

3% j 7 1 0mm 1 fiawza'ew ATTORNEY v M. .4

United States Patent ABSTRACT OF THE DISCLOSURE In the preferred form of this refrigerator, an upper above freezing compartment is divided by a horizontal glass or clear plastic partition into upper and lower subcompartments. An evaporating portion of a secondary refrigerant circuit is wrapped around the side and rear walls of the upper subcompartment to keep it at low temperatures and high humidity. The primary refrigerant evaporator is partitioned to provide a first section through which air is circulated by a first fan exclusive from and to the below freezing compartment. A second fan circnlates air from the lower subcompartment through a second section of the primary evaporator thence into heat transfer with the condenser of the secondary refrigerant circuit before returning it to the lower subcompartment. The humidity in the upper subcompartment is controlled by an adjustable discharge of air into it from the second fan circuit.

In a second form, the primary evaporator is provided with a final portion located directly in heat transfer with the condenser of the secondary refrigerant circuit.

This invention pertains to a household refrigerator in which the below and above freezing storage compartments are kept free of frost and the above freezing compartment is divided into lower and high humidity subcompartments. The higher humidity of the latter is obtained by providing extensive portions of the Walls thereof with an evaporator portion of a secondary refrigerant circuit. The condenser portion of this secondary circuit is cooled by the air cooled in turn by the primary evaporator or by the last or tailing portion of the primary refrigerant evaporator.

Household refrigerators have three principalrequirements, one of which is the freezing of liquid and foods and the storage of frozen products. A secondary requirement is to provide storage under sufficiently high humidity and low temperatures to prevent any substantial dehydration or growth of mold or bacteria on uncovered fruits, vegetables or other food. The third function is the storage at low humidities and low refrigerating temperatures of foods and liquids which are sealed such as covered jars, containers, dishes, bottles and cans.

It is an object of this invention to provide a refrigerator having below freezing and above freezing compartments in which a high humidity is maintained in one subcompartment and in another subcompartment, a lower humidity is maintained by the circulation of cold air.

It is an object of this invention to provide such a refrigerator in which the condenser of the secondary refrigerant circuit is cooled by the air being delivered to the low humidity storage compartment.

It is another object of this invention to provide a refrigerator in which the condenser of the secondary refrigerant circuit is cooled by the refrigerant in the last section of the primary evaporator which is also used for cooling bottles, cans and food in closed containers in one of the compartments of the refrigerator.

These and other forms are attained in .the forms shown in. the drawings in which the upper, above'freezing com- 3,394,557 Patented July 30, 1968 partment is divided by a horizontal glass or clear plastic partition. An evaporating portion of a secondary refngerant circuit is wrapped around the side and rear walls of the uppermost subcompartment which makes it possible to maintain a relatively high humidity in this subcompartment. The high humidity is manually controlled through the use of an adjustable air discharge into the high humidity subcompartment. By rotating the rotatable air control device, the humidity within the compartment may be varied. The evaporator of the primary refrigerant circuit provides a first section through which air is circulated by a first fan exclusively with the below freezing compartment. Air is also circulated by a sec ond fan through the lower humidity compartment exclusively with a second section of the primary evaporator. The first fan is cycled along with the sealed motor compressor by a temperature responsive switch responsiv to the temperature of the below freezing compartment. The second fan is controlled by a theromstatic switch responsive to temperatures in the high humidity compartment. A portion of the air circulated by the second fan is circulated in heat transfer with the condensing portion of the secondary circuit at the rear near the top of the cabinet. In a second form of the invention the condenser portion of the secondary refrigerant circuit is also located near the top of the cabinet at the rear but it is cooled directly by the final portion of the primary refrigerant evaporator.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is an upright front view with the doors removed of a household refrigerator embodying one form of my invention;

FIGURE 2 is an irregular side sectional View taken along the lines 22 of FIGURE 1;

FIGURE 3 is a view in elongation of a refrigerator with the doors removed illustrating a second form of the invention.

Referring now more particularly to FIGURES l and 2, there is shown a refrigerator cabinet having insulated side walls 20, an insulated rear wall 22, insulated top and bottom walls 24 and 26 together with an insulated horizontal partition wall 28 separating the interior of the cabinet into a lower below freezing compartment 30 and an upper above freezing compartment 31 itself separated by a horizontal dividing wall 33 of glass or plastic which separates the upper high humidity compartment 35 from the lower subcompartment 37. The upper door 19 seals against the front edge of the dividing wall 33. The compartment 30 is closed by a door 18.

At the rear of the compartment 30 parallel to the rear wall 22 there is provided a vertical partition wall 32 behind which is a vertical cross fin and tube evaporator 34. Beneath the evaporator 34 is an entering plenum 36 which is divided by a small vertical partition wall 38. Above the evaporator 34 is provided a second vertical partition wall 40 which is aligned with the wall 38. These two partition walls 38 and 40 divide the plenum 36 below the evaporator 34 and the plenum 42 above the evaporator 34. These upright wall portions 38 and 40 also cooperate with the vertical finned evaporator 34 to separate the evaporator 34 into a first section 44 on the left side of the upright dividing walls 38 and 40 and a second section 46 on the right side of the partition walls 38 and 40. The plenum chamber 36 on the left side of the partition wall 38 is provided with a long horizontal inlet opening 48 in the partition wall 32 adjacent the bottom wall 26. Above the evaporator 34 the partition wall 32 is provided with an opening 50 containing a four bladed propeller type fan 52 driven by a suitable electric motor 54 which draws in air from the below freezing compartment 30 through the opening 48 and through the left section 44 of the evaporator 34 into the plenum 42 where it is discharged by the fan 52 forwardly into the below freezing compartment 30. The fan motor 54 as well as the sealed motor compressor unit 56 are connected in parallel across the supply conductors L1 and N, but in series with the thermostatic switch 58 in the supply conductor L-1. A bellows 60 operating through a snap action mechanism closes and opens the switch 58. The bellows 60 is connected by a capillary tube 62 to the thermostat bulb 63 located in the upper portion of the below freezing compartment 30.

The lower humidity compartment 37 is provided with a drawer type meat keeper pan 64 supported upon the supports 66 on the lower left side wall. The meat keeper pan 64 is provided with a cover 68 for preventing the drying of the meat. Behind this meat keeper pan is an air outlet 70 provided in the lower left portion of the rear wall 22 behind the pan 64. This outlet 70 connects with a duct 72 also in the rear wall, extending diagonally downwardly to the lower right corner of the rear wall 22 where it is provided with an air discharge opening 74 discharging the air from the lower humidity compartment 37 into the portion of the plenum 36 on the right side of the partition wall 38 beneath the second section 46 of the evaporator 34.

On the right side of the vertical partition wall 40 there is provided a second propeller type fan 76 in front of an opening 78 in the rear wall 22. This four bladed propeller type fan is driven by an electric motor 80 under the control of a thermostatically operated switch 82 provided with an operating bellows 84 connected by a capillary tube 86 to the thermostat bulb 88 located in the upper portion of the lower humidity compartment 37. The fan 76 draws the air from the portion of the plenum 36 beneath the evaporator portion 46 up through the evaporator portion 46 and thence rearwardly through the entrance 78 of the wide upwardly extending ogee shaped duct 90 in the rear wall 22 having a first small round outlet 92 discharging air behind the upper right corner of the meat keeper 64. The duct 90 also has a larger outlet 94 adjacent the center of the rear wall 22 beneath the partition wall 33 from which the major portion of the air cooled by the section 46 is discharged to provide a strong circulation of the cooled dry air at above freezing temperature within the low humidity compartment 37.

The duct 90 narrows above the opening 94 and continues upwardly to the T-shaped upper end portion 96. This T-shaped upper end portion 96 includes a triangular shaped island 98 which directs the cold air flow around the inclined condenser portion 121 of the secondary refrigerant circuit 123 having an evaporator portion 125 looped around the side and rear walls of the sheet metal liner 127 above the horizontal partition wall 33. This cold circulating air in the T-shaped portion 96 cools the condensing portion 121 causing recondensation of the liquid which vaporiz'es in the evaporating portion 125 and recondenses in the condensing portion 121 and returns to the evaporating portion 125. Through this evaporation and recondensation of the refrigerant in the secondary circuit 123, the walls of the higher humidity compartment 35 are cooled sufliciently to maintain the atmosphere in this compartment just above 32 F. This method of cooling results in the maintenance of a high humidity and cold temperatures in the compartment 35 with a relatively small amount of air circulation therein. This prevents the rapid dehydration of any food stored in the compartment 35 and also prevents rapid growth of bacteria and mold. The T-shaped portion 96 discharges into a downwardly extending duct 129 extending within the rear wall 22. At the side of the upwardly extending portion of the duct adjacent the aperture 94, the duct 129 makes a 90 turn and terminates adjacent the discharge outlet 131 in the upper right hand corner of the lower humidity compartment 87 where it improves the circulation and makes the temperature more uniform.

According to my invention, the humidity within the compartment 35 is controlled by the discharge of air through an adjustable rotatable damper 133 having four triangular shaped openings interspersed with imperforate portions of similar size which are adapted to cover or uncover four similar openings in the adjacent wall of the duct 129. This form of damper has been used on stoves for many years. This damper 133 is adjusted to admit air at any desired rate from the duct 129 into the high humidity subcompartment 35. This additional dry air will reduce the humdity within the compartment 35 to the extent desired. The compartment 35 is provided with suitable shelving.

A modified form of the invention is disclosed in FIG- URE 3 in which similar parts retain the same reference characters as in FIGURES 1 and 2. This form differs from FIGURES 1 and 2 in the use of the refrigerant flowing through the evaporator 34 for cooling the condensing portion of the secondary refrigerant circuit in the omission of the supply of air to the higher humidity compartment 35. In FIGURE 3 the fan 76 delivers the air through a simple ogee curve duct 137 in the rear wall 22 to the small outlet 92 behind the meat keeper 64 and to an upper outlet 139 in the rear wall near the top of the lower humidity compartment 37 in a location similar to the outlet 94 in FIGURE 1. The duct 137 differs from the ducts in FIGURE 1 in that it terminates with a Wall 141 directly above the outlet 139.

To cool the condensing portion of the secondary circuit 123 in the form shown in FIGURE 3, the second section 46 of the evaporator 34 is extended by tubing 143 connected as a tailing portion of the evaporator. This tubing 143 extends upwardly through the rear wall to an evaporating portion which is embodied in a divided container 145 having an evaporating chamber 147 separated from the condensing chamber 149 by a heat transfer partition wall 151. The condensing chamber 149 forms the condensing portion 123 of the secondary circuit which is cooled through the partition wall 151 'by the refrigerant in the form of mixed gas and liquid in the evaporating chamber 147 delivered by the tubing 143. The vapor in the chamber 147 is removed through the suction conduit 153 which extends to the inlet of the sealed motor compressor unit 56. Whenever the sealed motor compressor unit operates, refrigerant will be delivered to the condenser 155 and to the evaporator 34 including the evaporating chamber 147 where the refrigerant through the partition wall 151 will cool and condense vapor in the condensing chamber 149 constituting the condensing portion of the secondary refrigerant circuit 123. This will keep the subcompartment 35 cooled to low refrigerating temperatures with high humidity. This high humidity is inherent in the cooling of the subcompartment 35 through its outer walls. Other details of the cabinet, the evaporator 34, the sealed motor compressor 56 and the condenser 155, as well as other details, may be like those illustrated in Patent 3,252,292 issued May 24, 1966.

While the embodiments of the invention as herein disclosed constitute a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A refrigerator having insulating means enclosing and separating an above freezing compartment and a below freezing compartment, wherein the improvement comprises means for separating said above freezing compartment into lower and higher humidity subcompartments, a refrigerant evaporating means, means for circulating air from said below freezing compartment into heat transfer with said evaporating means and returning cooled air to said below freezing compartment, means for circulating air cooled by said evaporating means through said lower humidity subcompartment, and a secondary refrigerant circuit having an evaporating portion in heat transfer relation with said higher humidity subcompartment and having a condensing portion cooled by said evaporating means.

2. A refrigerator as defined in claim 1 in which the evaporating means has first and second sections and the air from the below freezing compartment is circulated exclusively in heat transfer with the first section and the air from the low humidity compartment is circulated in heat transfer with the second section.

3. A refrigerator as defined in claim 1 in which the evaporating means has first and second sections and the air from the below freezing compartment is circulated exclusively in heat transfer with the first section and the air from the low humidity compartment is circulated in heat transfer with the sec-0nd section and the condensing portion of said secondary refrigerant circuit.

4. A refrigerator as defined in claim l in which the evaporating means has first and second sections and the air from the below freezing compartment is circulated exclusively in heat transfer with the first section and the air from the low humidity compartment is circulated in heat transfer with the second section and the evaporating means has a portion in heat transfer relation with said condensing portion of said secondary refrigerant circuit.

5. A refrigerator as defined in claim 1 in which the high humidity subcompartment is located above the low humidity subcompartment and the below freezing com- 6 partment and the condensing portion is located adjacent the upper portion of the high humidity subcompartment.

6. A refrigerator as defined in claim 1 in which the means for circulating air from the lower humidity subcompartment comprises means for discharging a small amount of air into said higher humidity subcompartment.

'7. A refrigerator as defined in claim 1 in which the means for circulating air through said lower humidity subcompartment comprises fan means responsive to the temperature of said lower humidity subcompartment.

8. A refrigerator as defined in claim 1 in which the humidity of the higher humidity subcompartment is controlled by means providing the discharge of air from one of said means into said higher humidity subcompartment.

9. A refrigerator as defined in claim 1 in which the humidity of the higher humidity subcompartment is controlled by means providing the discharge of air from one of said means into said higher humidity subcompartment, and means for varying said rate of discharge of air to vary the humidity in said high humidity subcompartment.

References Cited UNITED STATES PATENTS 2,416,354 2/1947 Shoemaker 62-334 2,442,188 5/1948 Bauman 62333 2,450,823 10/1948 Bauman 62-333 2,594,036 4/1952 Knapp 62-334 WILLIAM I. WYE, Primary Examiner. 

